THE SUMMIT meeting of the leaders of Japan's giant communist neighbors is generally welcomed here. Experts see it as a positive outcome of a shift in world affairs toward placing greater emphasis on economic development rather than military security. The summit, Japanese analysts say, will expand economic cooperation in East Asia and further ease tensions in the region. And it may help to soften the Soviet stance toward Japan, including the dispute over Soviet possession of the so-called Northern Territories, a group of islands in the Kurile chain which Japan claims.
``Normalization between the Soviet Union and China is a nice thing,'' says Kenji Tanaka, director of the Analysis Division of the the Foreign Ministry. ``So long as the present relationship between China and Japan is to be continued, I think nothing worries us.''
In the past, Japanese conservatives were pleased to have the Soviet Union and China at odds, viewing the split as a means of maintaining a balance of power in the region. A return to the friendly Sino-Soviet alliance of the 1950s would be generally perceived here as a threat to Japanese security. But few here are worried since most analysts see a renewal of this alliance as unlikely.
``I think there's some kind of limit beyond which the relations cannot go,'' says Mr. Tanaka. China, he observes, is eager to continue its access to the technology and capital offered by the West. ``China cannot develop relations with the Soviet Union to the extent that could jeopardize relations with us,'' he says.
Japanese analysts say China and the Soviet Union are drawn together by the urgency of economic reform and the need to reduce the drag of military spending.
``The nations that lost in an economic competition [China and the Soviet Union] intend to cooperate with each other by reducing the military,'' says Susumu Yabuki, a professor at Yokohama City University, who calls the reconciliation ``the solidarity of the weaks.''
The normalization may also encourage regional economic cooperation. According to China specialist Nobuo Maruyama, Chinese academics and researchers have been floating the idea of organizing a Northeast Asian common market, including China, Taiwan, Korea, Japan, and the Soviet Far East.
``Sino-Soviet rapprochement would create such an opportunity to build a Northeast Asia market area,'' he says.
The outlines of a ``division of labor'' between the countries of the region are already emerging, says Mr. Maruyama, a specialist at the Institute for Developing Economies.
Chinese labor is being used in the Soviet Far East. South Korean and Taiwanese capital is being invested in China. Soviet machinery is being exchanged for Chinese agricultural goods. Analysts say this growth will in turn create new markets for Japan.
The reduction of tension in the region is also viewed as a positive outcome for Japan.
``International politics has moved on a premise that China and the Soviet Union confront each other,'' says Akio Kimura, professor of International Politics and Economics at Tokyo's Aoyama Gakuin University. ``But, such confrontation, which lasted for the last 25 years, will disappear.''
The reconciliation, Professor Kimura says, ``makes it easier for Japan to deal'' with the two nations. In the past, he points out, ``when Japan was going to improve relations with the Soviet Union, China always got nervous.''